Which of the following are measures of quality: A. validity B. accuracy C. precision D. All of the above E. None of the above

The correct answer is: D. All of the above

Validity, accuracy, and precision are all measures of quality.

• Validity is the extent to which a measure accurately reflects the concept it is intended to measure. For example, a measure of intelligence that is highly correlated with academic performance is said to be valid.
• Accuracy is the extent to which a measure is free from error. For example, a measure of weight that is accurate to within 0.1 pounds is said to be accurate.
• Precision is the extent to which a measure yields consistent results. For example, a measure of blood pressure that yields the same result on repeated measurements is said to be precise.

All three of these qualities are important for a measure to be considered reliable and useful. A measure that is not valid is not measuring what it is supposed to measure, and so is not useful. A measure that is not accurate is not measuring the concept it is intended to measure with any precision, and so is not useful. And a measure that is not precise is not yielding consistent results, and so is not useful.

Therefore, all three of validity, accuracy, and precision are important measures of quality.